© 2004 Robert A. Freitas Jr. and Ralph C. Merkle. All Rights Reserved.

Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004.

6.4.4 Exemplify a Benign Design

An acceptable molecular assembler or nanofactory design should be safe, incapable of “natural evolution,” and pollution-free.

(1) Demonstrate the Design is Safe. The system design should be inherently safe (Section 5.11), in the sense that it should not pose the kinds of extraordinary dangers that some have imagined are inevitable for replicating systems [2909]. One primary route for insuring this is to employ the broadcast architecture for control [209]. As discussed in Section 4.11.3.3, the broadcast architecture virtually eliminates the likelihood that the system can replicate outside of a very controlled and highly artificial setting. The design should not describe a replicator that will directly compete with humans, or other biological entities, for the resources necessary for production or self-replication. Note that while a diamondoid molecular assembler would primarily employ carbon atoms in its construction, and carbon is also the principal atom used in biology, the carbon source for assemblers is not complex organic molecules and structures but rather the simplest hydrocarbons such as acetylene or butane, hence such assemblers will not be competing with biology for carbon resources.

(2) Design for Nonevolvability. The system design should not permit any capacity for endogenous evolution of new structures or new capabilities, as discussed in Sections 2.1.5, 5.1.9 (L), and 5.11.

(3) Clean Manufacturing and Pollution-Free Operation. Another important design objective is to minimize or eliminate all material waste products generated by replicative or productive activities. Components, subsystems and systems should not be needlessly thrown away during the replication or manufacturing cycle. The source of this objective is not mere environmentalist sentiment and aesthetics, but rather a strong practical desire for manufacturing efficiency. The greater the amount of waste that is produced, the more machine operations (both onboard and offboard) must be devoted to handling and disposing of this waste, which increases manufacturing time per unit mass of product, imposes greater burdens on materials import and export subsystems, produces more waste heat, and modestly increases the possibility of device failure because of the extra processing and transport steps that must be successfully performed. A manufacturing system which produces zero pollution, as exemplified by the Merkle-Freitas Hydrocarbon Molecular Assembler (Section 4.11.3), would be extremely desirable.

Last updated on 1 August 2005